Auditory Brainstem Implantation in Neurofibromatosis Type 2: Experience From the Manchester Programme.

OBJECTIVE: To describe the experience of auditory brainstem implantation (ABI) in patients with Neurofibromatosis type 2 (NF2). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral centre. PATIENTS: Implanted with a Cochlear ABI22 or ABI24M between 1994 and 2009 because of NF2 disease. INTERVENTION(S): Rehabilitative. MAIN OUTCOME MEASURE(S): Surgical complication rate; audiological outcomes. RESULTS: There were 50 primary ABI insertions in 49 patients, including 16 inserted at the time of first side tumor removal as a sleeper, and two revision repositionings which failed to improve outcome. Postoperatively three patients had cerebrospinal fluid leaks which did not require reoperation, one patient had meningitis, and eleven patients suffered either temporary or permanent lower cranial nerve dysfunction. Twenty-nine patients became full time users; a further 12 patients became non-users. Three patients died while their device was inactive. Five patients retain serviceable contralateral hearing. Audiological open set testing of users showed means of: environmental sounds discrimination 51%; phoneme discrimination: with ABI alone 22%/lip reading (LR) 45%/ABI with LR 65%; sentence testing: with ABI alone 13%/LR 19%/ABI with LR 54%. CONCLUSIONS: The majority of patients with NF2 implanted with an ABI find the device a useful aid to communication in conjunction with LR and in recognizing common environmental sounds. A small proportion gain open set discrimination. Almost a third of patients may end up as non-users. There is probably an increased risk of postoperative lower cranial nerve dysfunction so careful preoperative assessment is advised.

Clinical and radiological guidance in managing facial nerve schwannomas.

OBJECTIVE: To present a review of all patients diagnosed with a facial nerve schwannoma (FNS) managed in our center over almost two decades, and suggest guidelines for their classification and management. STUDY DESIGN: Retrospective case review SETTING: Tertiary referral center PATIENTS: Twenty-eight patients with a facial nerve schwannoma INTERVENTION: Conservative or surgical management depending on clinical and radiological features MAIN OUTCOME MEASURE: Patient demographics, site of tumor, and clinical symptoms, including facial nerve function (House-Brackmann score) at baseline and follow-up. In those managed surgically, operative approach and surgical outcomes were also recorded. RESULTS: Of 28 patients, 16 were male. Mean age at presentation was 46 years. The majority presented with either facial weakness or hearing loss. The internal auditory canal segment of the facial nerve was the most commonly affected (19/28, 68%). Multi-segmental lesions were found in almost half (46%) of patients. Facial weakness was most commonly associated with involvement of the labyrinthine segment (89%). Overall, 16 (57%) patients were managed surgically. CONCLUSION: FNS may be difficult to distinguish on both clinical and imaging grounds from other cerebellopontine pathologies on the basis of audiovestibular symptoms alone. The presence of facial weakness in combination with imaging findings suggestive of FNS is highly suggestive for FNS. In patients with brainstem compression, rapid tumor growth, or House-Brackmann greater than 4, we suggest a surgical approach based on preoperative audiovestibular status, helping optimize long-term facial function and minimize morbidity. Facial nerve reanimation at the time of primary surgery is preferred.